<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>margin的注意事项四</title>
    <style>
        div {
          width: 400px;
          height: 400px;
        }
        .d1 {
          background-color: blue;
        }
        .d2 {
          background-color: #ffccff;
          margin-top: -200px;
        }
    </style>
</head>
<body>
<!--    外边距可以是负值 会和上面的元素重叠 -->
    <div class="d1">d1</div>
    <div class="d2">d2</div>
</body>
</html>